The fungal genus Tricholomopsis (Agaricales) in New Zealand, including Tricholomopsis scabra sp. nov. Author Cooper, Jerry A. Landcare Research, PO Box 69040, Lincoln 7640, New Zealand Author Park, Duckchul Landcare Research, Private Bag 92170, Auckland 1142, New Zealand text Phytotaxa 2016 2016-12-09 288 1 69 76 http://dx.doi.org/10.11646/phytotaxa.288.1.7 journal article 302151 10.11646/phytotaxa.288.1.7 f595c94c-5851-43fd-89ad-b55622aced5b 1179-3163 13644520 Tricholomopsis ornaticeps (G. Stev.) E. Horak The following description is emended from Stevenson (1964) , Horak (1971), and examination of New Zealand collections, including the holotype , enumerated in Table 1 . Macro-morphology :―Pileus 70–80 mm diam., convex with down-rolled margin becoming centrally depressed, ochraceous to saffron yellow, thickly covered with minute brown fibrillose scales. Lamellae moderately distant, attachment sinuate, yellow, staining brown at edges. Stipe 30 × 10 mm , creamy above, ochraceous at base, fibrillosestriate. Context creamy yellow in pileus and continuous with stipe. Spore print white. Gregarious on ground and associated with decaying wood. Micro-morphology :―Spores oval to subcylindrical, neither amyloid nor dextrinoid, hyaline, thin-walled, with hilar appendage, length 8.3 μm (σ = 0.54) × 4.3 μm (σ = 0.32), Q = 2.0 (σ = 0.16), n = 20. Basidia 20–40 × 8–10 μm, narrowly clavate, 4-spored. Lamella edge sterile. Cheilocystidia conspicuous, thin-walled, some with yellow plasmatic pigment in KOH, 30–100 μm long × 10–30 μm diam., multi-septate, constricted at septa and often appearing like chains, terminal cells obovoid to broadly cylindrical. Clamp connections present in all tissue. Pleurocystidia absent. Pileipellis a cutis of loosely woven hyphae about 5 μm diam.; scales are aggregations of parallel hyphae 3–5 μm diam., with thickened walls which are rusty brown in transmitted light. FIGURE 3. Tricholomopsis ornaticeps . A) water colour (G.M. Taylor), PDD 84171, scale 15 mm; B) cheilocystidia (composite image), PDD 82501, scale = 75 μm; C) spores (composite image), PDD 84171, scale = 20 μm; D) cheilocystidia, PDD 102517, scale = 40 μm. Photos: B, C, D by Jerry Cooper. Habitat and distribution :―occasional in North Island and upper South Island in native beech forest, and in exotic conifer plantations of Pinus radiata and Larix spp . Comments:— T. ornaticeps ( Fig. 3 ) is easily distinguished microscopically by its elongate spores and cheilocystidia often appearing to be chained. Macroscopically it is distinguished from T. rutilans by the lack of plum colours, and from T. scabra by its less scabrous pileus and occurrence in beech forest and plantations.